1. Field of the Invention
The present invention relates to a multi-type air-conditioning apparatus having a plurality of indoor units connected to a heat source unit.
2. Description of the Related Art
When a refrigerant is filled in a refrigerating cycle of an air-conditioning apparatus, and a refrigerant amount is small, the air-conditioning apparatus cannot be properly operated.
In general, when a simple refrigerating cycle is used, checking whether a refrigerant amount in the refrigerating cycle is enough to operate the air-conditioning apparatus can be performed by detecting temperatures of parts of the refrigerating cycle, although the checking is difficult. As an example, an air-conditioning apparatus is described in Published Unexamined Japanese Patent Application No. 4-148170.
However, in a multi-type air-conditioning apparatus having a plurality of indoor units connected to a heat source unit, the arrangement of the refrigerating cycle is complicated, and there are a large number of combinations of the shapes and capacities of the indoor units. For this reason, a refrigerant amount cannot easily be determined in consideration of an indoor environment.
It is assumed that a protector is operated due to any abnormal operation in a test operation of the apparatus after the apparatus is installed and that the operation is stopped. In this case, assuming that a lack of refrigerant may cause the abnormal operation, although it is not known that the lack practically causes the abnormal operation, a normal amount of refrigerant must be recharged into the refrigerating cycle.
In this case, installation of the apparatus is delayed, time and cost are wasted, and the reliability of an operator may be impaired. In addition, when the refrigerant is recharged, the refrigerant filled in the cycle may be discharged to the outer atmosphere. Even if flon gas (R-22) used as a refrigerant is excluded from objects of anti-pollution regulations, discharge of a large amount of flon gas, i.e., several tens Kg, adversely affects the environment.
An example of the air-conditioning apparatus having a plurality of indoor units connected to a heat source unit is described in Published Unexamined Japanese Patent Application No. 4-222358.